Brief Description of the Prior Art
Electrically powered ceiling fans are widely utilized as a method of environmental comfort control within dwellings and in business establishments, and in such usage, are mounted from room ceilings which greatly vary in their height above the floor. Because of this variation, some ceiling fans, as manufactured and installed by the consumer, are suspended from the ceiling in a position such that the rotating fan blades are dangerously close to the heads of tall persons standing in the room. In other rooms having relatively high ceilings, there is little danger of injurious contact with the fan blades, and for this reason, it is always desirable to mount the blades at a location spaced sufficiently below the ceiling that optimum circulation of air is obtained by the rotation of the blades.
Because of the variable vertical dimensions of the spaces within which ceiling fans are used, it is desirable to provide a structure which can be quickly altered so as to permit the fan to be either mounted in a flush mount mode, where the blades are close to the ceiling, or in a suspended down rod mode, where the rotating blades are an optimum distance from the ceiling in terms of the air circulation which is effected.
One such construction providing an easily used option for mounting a ceiling fan in a flush mode, in which the blades are closely adjacent the ceiling, or in a down rod mode of the type described, is the fan construction disclosed in U.S. patent application Ser. No. 913,475, U.S. Pat. No. 4,729,725. In converting from a down rod mounting arrangement to a flush mounting arrangement, the down rod of the fan is eliminated, and the canopy which is used to suspend the fan from the ceiling is secured directly to the upper side of the fan housing so that the fan blades are thereby shifted to a location relatively close to the ceiling. When the down rod mode is used, the down rod is extended through an opening in the center of the canopy, and the fan motor housing and blades are then secured to the lower end of the down rod, and as such, are spaced an optimum distance downwardly from the ceiling.
Although the described structure facilitating the optional mounting of the ceiling fan in either a flush mount mode or a down rod mode can be easily utilized with a fan of the type illustrated and described in such application, in which the housing for the fan motor is stationary and can be secured directly to the canopy after removal of the down rod, this structure is inadequate to permit a very popular type of ceiling fan now being marketed to be flush mounted in the manner described. This is a ceiling fan in which the blades are secured to the fan motor housing, and both the motor housing and blades are then caused to rotate about a central axis when the fan is operated. This type of fan offers certain advantages over other types currently marketed, and it would be desirable if such a fan could be flush mounted quickly and easily as an optional mode of mounting alternative to the down rod mode of mounting.